Bob and Tim have had a big day at work — it’s 3:30 in the afternoon, and they are done for the day. They’re having coffee at a local restaurant, talking about their careers when Tim asked a question, “What is a ton of refrigeration, and why is it called a ton?”

Whether the commercial refrigeration equipment you’re working on is a small under-counter refrigerator, a keg refrigerator, a large walk-in freezer, or a transportation refrigeration system, many of the technical concerns will be the same.

Bob and Tim were on their way to a no heating call. When they arrived, they looked at the house and saw that it had a package unit. They talked to the housewife and she told them that the unit stopped running sometime in the middle of the night last night.

In this troubleshooting situation, the equipment that needs servicing is a condensing gas furnace in a relatively small home of approximately 1,200 square feet. The capacity of the unit is 40,000 Btu and it is equipped with an LED readout system.

Bob and Tim were checking a customer's air conditioner and initially thought the unit must be out of refrigerant or very low on refrigerant. But after adding some refrigerant, the suction pressure did not rise at all. Bob then determined they should look for restrictions in the liquid line or the suction line.

No matter the type, properly designed, specified, installed, and maintained humidification systems can provide years of trouble-free operation. Taking a proactive approach to humidifier maintenance is the single best way to prevent operational issues and unscheduled humidification system shutdowns.

Bob and Tim were at a customer’s house doing a seasonal checkup on a condensing gas furnace. This was routine service carried out every year on this customer’s equipment per a service agreement. But when they tried to operate the furnace, the burner would not light.

In this month’s troubleshooting situation, you’re responding to a customer’s complaint that his furnace isn’t heating properly. The equipment is an 80 percent AFUE, natural gas, induced draft unit that employs a hot surface ignition system.

A customer was explaining what was going on with his air conditioning system. His old system had stopped working and he was told that it needed to be replaced. Money was tight and a cousin had a system removed from a rental property. So they replaced the original 3-ton package unit with a 4-ton package unit.

According to the U.S. Environmental Protection Agency (EPA), when businesses invest in energy efficiency, it yields 200-300 percent return on investment (ROI). Steps taken to make HVAC systems more efficient are beneficial for both business profitability and sustainable resources.